DE2164933A1 - Capillary material of synthetics - comprising non - or low-polar synthetics assembled into body with connected voids of smal - Google Patents

Abstract

Capillary material for the capillar transport of aqs. or non-aqs. liquids by capillary elevation is made from non-polar, e.g. polyethylene of Debye index 0, or only slightly polar, e.g. 3.4 Debye index polyacrylonitrile, synthetic material in modified form for forming the capillary walls. The materials is in the form of mono-filament, staple or fibrillated film fibres with small cross-section, twisted, glued, bound or pressed, sintered, or fabricated by weaving, knitting or non-woven techniques. Dia. of the fibres is pref. >3 mu and dia. of the spaces is 2 - 1000 mu.

Description

Copillary material for liquid transport and process for its Manufacture The invention relates to a capillary material, i. H. a material which is interspersed with continuous cavities, the one such Length and dimensions have a capillary effect through these cavities takes place to transport a liquid. The invention also gives a preferred one Process for the production of such a material.

It is known that capillary phenomena at the boundary between solid and liquid or occur between two liquid bodies. These appearances cause, for example, water in a narrow, immersed in the water surface Glass tube (capillary) rises above the outer water level. This process will called K @ pillarascension. There are other liquids like mercury which are pressed down in such a capillary. This phenomenon becomes capillary depression called.

The prerequisite for a capillary ascension ion, as it is with various organic materials such as linen, cotton or glass and asbestos fibers, occurs, however, is the most complete possible wetting by the respective liquid. For water there is an affinity for a solid if this is the one possible has a polar character and does not contaminate the surface with hydrophobic substances is.

Capillary ascension is often used in institutions for capillary liquid transport. These facilities are for example in many textile products, e.g. B. clothing, drainage, absorbent paper, medical Bandages, in central heating evaporators, in dispensers or the like. More, used.

After the artificial macromolecular plastics became known there was a need because of the good chemical and physical properties these substances with a view to the purposes indicated above also these for Manufacture of capillary materials to use. As a result of their non-polar or also only very weakly polar in character, resulting in a low wettability, for example by water, there was sufficient capillary ascension not to be expected from these substances. This corresponds to the state of the art One came to the conclusion, among other things. by the results of contact angle measurements on plastic sheets.

The invention has now set itself the task of a capillary To create a material and a method for its production, in which the above listed macromolecular Plastics can be used. To solve the problem, a capillary material becomes a capillary ascensive material Proposed liquid transport, which is characterized in that macromolecular Plastics with a non-polar character, such as polyethylene with O Debye, or only very weakly polar in character, such as, for example, polyacrylonitrile with 3,4 Debye, in modified form as solids for the formation of the capillary walls be used.

It has been shown that by a certain modification of the aforementioned Plastics a sufficient capillary ascension can be achieved, whereby this Substances can then be used for the stated purpose.

The solid body can be used as a plastic monofilament or staple fiber or fibrillated film with a square, rectangular, round or shapeless Cross-section of> 3 my can be formed. These solids become tight and parallel packed together and, for example, by twisting, twisting, wrapping, compressing, e.g. between plates or in tubes, partial welding, sintering, weaving or Working, producing non wove @ fobric @ s or similar measures in which final Form made. The liquid rises as a result of capillary forces then in the channel-shaped or columnar shape formed between the solid filaments Gaps with a cross section of 2 - 1000 my. With a capillary cross-section of 2 my, the capillary depth is greatest, while it is at a cross-section of @ 1000 my goes to zero.

There is thus the possibility of defining the capillary cross-section to vary the capillary ascension at will, whereby these materials according to of the invention can then be used for the purposes indicated above.

According to the invention, yarns and textile products made therefrom can also be used made of plastics by the modification mentioned above with regard to their ability similar to yarns and woven products made of natural fibers for capillary ascension at will be made. This makes it possible to make textile products made of plastics from the serious To get rid of the disadvantage of not being able to absorb moisture. With those with Textile products made of plastic made from the material according to the invention, such as clothing, underwear, shirts or the like, then there is a capillary liquid transport both in the longitudinal direction of the arnes and across it.

Another advantage of the material according to the invention is, for example in the fact that / when used in drainage due to the plastic used no microbiological attack takes place.

But the good resistance also occurs in industrial applications of the plastic against acids and bases during capillary liquid transport in Appearance.

It is also possible to use the solid in the form of plastic films or plates. These are layered with a. defined distance packed together, which can vary between 2 - 1000 my. As a spacer between the foils or plates are additives to the starting raw material, which are in a or different properties of the material used. These additives, z. B. Plastics that differ in molecular weight from the material, silica or sodium chloride, cause a grainy or rough surface. Also can a rough surface of the foils and plates serve as spacers, e.g. through formulation, appropriate temperature program during plasticizing, the cooling rate, the haul-off speed or by subsequent finishing of the surface can be.

In a further embodiment of the invention, a method for Manufacturing proposed the material according to the invention, which is characterized is that the plastics mentioned during or before the formation of the capillaries a material change, for example through the addition of polar substances, such as Metal or glass traces, or experienced through special pigments. It is also possible by a chemical-physical $ change $ in the surface of the solid plastic body towards the formation of a polar structure, the capillary material to give desired properties. For example, by electrical Charging or electrical pretreatment in the high voltage fold the appearance of a Capillary ascension can be achieved0 The solid body can either be a spark discharge or exposed to a silent discharge, causing changes in its polarity Character with a view to achieving or improving the capillary ascension result. D it can also be achieved by applying a flame to the material.

According to a further embodiment of the method according to the invention is It is also possible to use macromolecular plastics to produce a material in the form of open cells Produce foams, in which the individual gas or air bubbles among each other are connected and each with a plurality of capillary tubes Ability to form capillary ascension. In general, any other continuous cavities are generated in the plastic body to this width to manufacture the capillary material according to the invention. So it is also conceivable Hollow fibers with any outer diameter and an inner diameter of 2 - to pack 1000 my together in a suitable manner in parallel or non-parallel and in this way to produce the capillary material according to the invention.

Based on the drawing, the example of a preferred embodiment the production of the capillary material according to the invention will be explained in more detail.

In the drawing, FIG. 1 shows a strand of solids composed of individual elements Threads according to the invention.

Fig. 2 shows the solid strand in cross section according to the invention.

Fig. 3 shows a capillary material made of foam material according to the invention.

Fig. 4 shows a capillary solid body, which consists of an individual There is plastic film or sheet.

As can be seen from FIGS. 1 and 2, there is a solid strand from individual plastic threads 1. The threads l are assembled so that between through them through cavities 2 arise, which as so-called quasi-capillaries serve and in which the liquid rises. The capillary material produced in this way can then be used for capillary liquid transport, for example with drainage Suction inserts for evaporators, dosing devices, etc., can be used.

The individual threads can be as plastic monofilaments or as plastic staple fibers with a very small diameter, they are then made by twisting, Drilling, gluing, wrapping, pressing, e.g. between plates or in tubes, partial welding, sintering, weaving or knitting, production of non woven fabric @ s or similar measures, so tightly compressed that small tubes between them or channel-shaped cavities in the longitudinal direction of the plastic monofilaments or plastic - staple fibers or arise across it. The plastic monofilaments or plastic staple fibers can thereby have a round, an angular or a shapeless cross-section and have a diameter of @ 3 my and cavities of round, angular or shapeless Form a cross-section with a smallest diameter of 2 to 1000 my.

The solid can also be in the form of Mohlfäden with any external Diameter and an inner diameter of 2 to 1000 my, whereby the hollow fibers are parallel or non-parallel by the measures described above so tightly packed that in the hollow fibers and / or between them a Fluid transport takes place as a result of capillary ascension.

As can be seen from FIG. 3, there is the capillary material shown there from a foam material which has been manufactured or processed in such a way that the individual cavities 3 are connected to one another by connecting conduits 4. As a result, the cavities with their connecting channels together form the capillary, and the material can be used in the same way as described above. Around To increase the capillary ascension, the fluid to be transported can also be increased surface tension-reducing agents Substances, e.g. surfactants, mixed in or the surface tension can be reduced by increasing the speed will.

The production of the material shown in Fig. 3 can be done by that first a foam is formed from the macromolecular plastic, the simultaneous or subsequent to a mechanical or @onetigen physical Treatment is subjected in such a way that the foam bubbles 3 siut @@@ Formation of capillary cavities 4 one below the other through the peeled material associate.

For this purpose, the foam can be used only or for predominantly have cells, the largest diameter of which is about 2 to 1000 my betzö @@ However, it is also possible to initially produce the foam with larger cells, @@ then deformed into lens-shaped structures by the action of external forces the smaller diameter is 2 to 1000 my.

It is also possible to create a copillary material by combining the two measures mentioned above, d. H. by producing fibers and foam, to manufacture.

Fig. 4 shows a capillary solid body made of individual plastic films or plates 5. These form columnar capillary cavities 7, what is achieved by a suitable rough surface or by spacers 6.

The production of the capillary material from plastic films or Plastic plates are made in such a way that initially foils of the plates 5 of any desired Thickness are produced, which are pressed together in a suitable manner so layered be that due to a special design of the surface roughness between the foils or plates formed cavities with the smallest diameter of 2 to 1000 my will.

The surface roughness k @@@@@@@ by means of suitable additives achieved for the starting raw material or subsequent application of suitable spacers will.

The macromolecular plastic with non-polar or only very weak polar character can occur before or during the formation of the capillaries by admixture of polar substances, such as traces of metal or glass, special pigments or the like, materially to be changed.

The macromolecular plastic with umpolar or only very weak polar character can also be chemically and physically on the surface in the way be treated so that a quasi-polar structure of the same results. This can for example by using a silent discharge or spark discharge in one High-voltage field, by flaming, by additives from a special Aviwvage or fluxes or oxidants and similar measures can be achieved.

The capillary material according to the invention can be used to transport liquids aqueous or non-aqueous liquids, for example in many textile products, z. B. clothing, in drains, for suction inserts in evaporators and central heating evaporators, as medical bandages, in dosing devices, absorbent papers or the like, to use with great advantage.

Claims (10)

P a t ent a n s p r u c h e 1. Capillary material for the transport of aqueous or non-aqueous Liquids by capillary ascension, e.g. for textile products, e.g. B. Clothing, in drains, suction inserts for evaporators, medical bandages, Dosing devices or the like, characterized in that macromolecular plastics with a non-polar character, for example polyethylene with 0 Debye, or only very weakly polar character, such as Psleacrylnitril with 3.4 Debye, in modified Form as solids to be used to form the capillary walls. 2. A method for producing a k @ apillary material according to claim 1, characterized in that the solid body initially as a plastic monofilament, Plastic staple fibers or fibrillated films with a very small diameter being, the plastic monofilaments or plastic staple fibers or fibrillated Films then by twisting, twisting, gluing, wrapping, pressing together, z. B. between plates or in tubes, partial welding, sintering, weaving or Working, producing non wovel fabric @ es or similar measures, so tight are pressed together that between them tubular, channel or column-shaped Hollow spaces in the longitudinal direction of the plastic monofilaments or plastic staple fibers or fibrillated films or with the ability to transport liquid by capillary ascension develop. 3. Procedure according to @@ @@@@@ 2. d a d u r c h g e k e n n n z e i c h n e t that the plastic monofilaments or plastic stackable fibers or fibrillated Foils have a round, an angular or a shapeless cross-section and have a diameter of> 3 ny and cavities v @@@@@@@@ dem, angular or formless cross-section with a k @@@ instas diameter from 2 to 1000 my will. 4. A method for producing a capillary material according to claim 1, characterized in that the solid body initially in the form of hollow fibers with any outer diameter and an inner diameter of 2 to 1000 my are, the hollow fibers then by suitable, as described in claim 2 Measures in parallel or are not packed together in parallel, that in the hollow fibers and / or between them a liquid transport as a result Capillary ascension takes place. 5. A method for producing a capillary material according to claim 1, characterized in that the solid body is initially in the form of films or plates any thickness is formed, which are pressed together in a suitable manner so layered be that through a special design of the surface roughness, which in turn through suitable additives to the starting raw material or subsequent application of suitable ones Spacer is achieved between the foils or panels with the smallest of cavities Diameter from 2 to 1000 my with capillary ascensive fluid transport capability $ are formed. 6. A method for producing a capillary material according to claim 1 or one or more of the following claims, characterized in that a macromolecular plastic with a non-polar or only very weakly polar character before or during the formation of the capillaries due to the admixture of polar substances, like metal or glass traces, special ones Pigments or the like, materially is changed and that from this materially modified plastic one with capillaries Cavities interspersed material is produced. 7. A method for producing a capillary material according to claim 1 or one or more of the following claims, characterized in that a macromolecular plastic with a non-polar or only very weakly polar character chemically and physically the surface is treated in such a way that a quasi-polar structure of the same results, for example by using a silent discharge or spark discharge in a high-voltage field, by flaming, by adding a special finishing agent or flux or oxidants and the like. Measures can be achieved. 8. A method for producing a capillary material according to claim 1 or 6, characterized in that initially by measures known per se a foam with the macromolecular plastic is formed at the same time or then a mechanical or other physical treatment in is subjected to the manner that the foam vesicles expand to form capillaries Cavities among each other through the entire material connect, with the foam only or predominantly without external force Part has cells whose largest diameter is 2 to 1000 my. 9. The method according to claim 8, characterized in that a foam is made with larger cells, which are then produced by external forces be deformed into lenticular structures, the smaller diameter of which is 2 to 1000 my is. 10. A method for producing a capillary material according to claim 1, characterized in that the material consists of a combination of the in claim 2, 6, 8 or 9 is produced.